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Mixing 2T oils?

Posted: Thu Nov 23, 2017 7:59 am
by grumps
Hi all,

In my recently acquired GT380 is a gold coloured oil in the CCI tank. My local restorer suggests it's probably just normal engine oil POs have been using instead of 2T oil (he says nearly all 2T oils are red??)

The suggestion is to run the oil really low then top up with a proper 2T oil.

If (If) it is normal engine oil then the chances are that it's at least a semi synthetic. If I then top up with a semi 2T oil all should be good - right??

I'm not good enough with this engine yet to want to drain the system and re-prime.

Does anyone use ordinary engine oil as a 2T?

Hoping this doesn't come across as a dumb question but my last 2T engine was 46 years ago and that was pre-mix.

BTW - the more I get to know the 380 the more I like it - reminds me of my youth - when I had no money to buy one.

All the best

David

Re: Mixing 2T oils?

Posted: Thu Nov 23, 2017 8:26 am
by Zunspec4
Hello David,

2-st oils come in a variety of colours. The Castrol A747 I use for racing is gold in colour for instance. The colour is just a dye added to the mix and I have seen oils in Red/Purple/Green/Gold colours. I would not run a 4-st oil as the engine oil in a 2-st if I could help. It should be relatively easy to drain the oil tank at the tank end, leaving the lines undisturbed. You will only then have to empty the lines and not the whole tank.

Cheers Geoff

Re: Mixing 2T oils?

Posted: Thu Nov 23, 2017 8:42 am
by grumps
Thanks Geoff

I have a vacuum brake bleeder pump that I might use down the filler of the tank, pump out as much oil as I can and then top up with 2T oil, run the bike until I can see the new oil in the pipes and all should be good. (I hope!)

Re: Mixing 2T oils?

Posted: Thu Nov 23, 2017 10:10 am
by GTandcbr
IMHO i would drain the tank and flush the oil feed pipes too. https://youtu.be/necW4LnXBHM" onclick="window.open(this.href);return false;
You have no idea what is contained in the oil tank it could be contaminated with anything. Just a heads up you cant mix mineral oil with synthetic as this causes the oil to 'gloop' which is similar to clotting. This is just my opinion its your bike and your choice.

Re: Mixing 2T oils?

Posted: Thu Nov 23, 2017 10:29 am
by grumps
Hhhmmm.? The PO was well into his 2 strokes but he didn't ride the bike much and only had it a few weeks so probably didn't put an oil in
.

The PO to him had it 5 years......(brain wave) I have his details so I might well ask. The stuff in there could well be pukka.


Don't you just love bikes? Thanks for the link.

Re: Mixing 2T oils?

Posted: Thu Nov 23, 2017 5:24 pm
by joolstacho
GTandcbr wrote:IMHO i would drain the tank and flush the oil feed pipes too. https://youtu.be/necW4LnXBHM" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
You have no idea what is contained in the oil tank it could be contaminated with anything. Just a heads up you cant mix mineral oil with synthetic as this causes the oil to 'gloop' which is similar to clotting. This is just my opinion its your bike and your choice.
+1 - Drain and change.
Why risk it, your whole engine is at stake just for the sake of a few bucks for fresh 2T oil.

Re: Mixing 2T oils?

Posted: Fri Nov 24, 2017 3:31 pm
by sportston
When I was at the young and stupid age of 16 I seized a 2-stroke while running on 4-stroke oil. Its not worth the risk, especially when an engine rebuild costs so much on a triple.

Re: Mixing 2T oils?

Posted: Sat Nov 25, 2017 12:29 pm
by grumps
I agree lads. I'll purge it and be done with it. Thanks

Re: Mixing 2T oils?

Posted: Sat Nov 25, 2017 1:04 pm
by sportston
grumps wrote:I agree lads. I'll purge it and be done with it. Thanks
A wise decision. Losing a few bucks worth of oil is a lot cheaper than an engine rebuild.

Re: Mixing 2T oils?

Posted: Sat Nov 25, 2017 1:40 pm
by grumps
To be fair I don't think either of the previous POs would skimp on oil but, hey-ho, not worth the small risk.

Re: Mixing 2T oils?

Posted: Thu Nov 30, 2017 9:51 am
by grumps
Is it easy to remove the oil pump without taking things like the carbs off too? It looks a bit congested around that area.

Thanks

Re: Mixing 2T oils?

Posted: Sat Dec 02, 2017 3:55 am
by grumps
Panic over I hope.

I managed to speak to the owner before last (last one only had it 3 weeks) who is a very nice guy and really helpful - and reassuring about the bike itself.

Oil is Silkolene Scoot 2 Semi-synthetic so I'll carry on with that for a while.

Thanks for all the posts lads, I really appreciate them.

David

Re: Mixing 2T oils?

Posted: Sat Dec 02, 2017 10:58 am
by GTandcbr
Great news save you some time but just one more bit of advice. Your local restorer who told you "The suggestion is to run the oil really low top up with a proper 2T oil" hasnt a clue about 2 strokes!

Re: Mixing 2T oils?

Posted: Sat Dec 02, 2017 11:11 am
by grumps
Thanks GT - future words of advice from him will be taken with a pinch of salt!

Re: Mixing 2T oils?

Posted: Sat Dec 09, 2017 1:34 pm
by grumps
So if two 2T oils are both JASO FC / API TC, are they basically the same and equally competent? Both semi synthetic 2T oils.

The Scoot2 is described as for scooters, mopeds and minibike engines. Any good for a GT380 engine?

Sorry about the questions - I'll get there eventually !!

Thanks